The rate and extent to which the active ingredient is absorbed from a pharmaceutical dosage form and becomes available at the site of action is defined as bioavailability (Chen, M. L. et al., Bioavailability and bioequivalence: an FDA regulatory overview, Pharm. Res. 2001, 18, 1645-1648). However, it is rarely feasible to measure the drug at the site of action. Therefore, bioavailability is assessed based on drug concentrations in the general circulation. The systemic exposure is determined by measuring the blood or plasma concentrations of the active drug at numerous time points following the drug administration and calculation of the area under the concentration-time curve (AUC). Blood/plasma drug concentration time profiles are affected by the dynamics of dissolution, solubility, absorption, metabolism, distribution, and elimination.
In principal drug absorption from a solid oral dosage form after administration can depend on the dissolution of the solid oral dosage form, which results from a series of simultaneous and successive processes and the permeability across the gut wall of the gastrointestinal tract. Depending on the Biopharmaceutical Classification System (BCS) of the drug substance in vitro dissolution may be relevant to the prediction of in vivo plasma concentrations and therefore bioavailability (Guidance for Industry, Dissolution Testing of Immediate Release Solid Oral Dosage Forms, U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER), August 1997).
Based on this general consideration, in vitro dissolution tests for immediate release solid oral dosage forms, such as tablets and capsules, are used to assess the quality of a drug product. An immediate release product allows the ingredient or active moiety to dissolve in the gastrointestinal tract, without causing any delay or prolongation of the dissolution or absorption of the drug. Requirements for dissolution testing of immediate release products are focused in the Guidance for Industry (CDER 1997) “Dissolution testing for immediate release solid oral dosage forms”, (CDER 1997) “Immediate release solid oral dosage forms—Scale up and Postapproval Changes”, ICH Guidance Q6A, Specifications: Test Procedures and Acceptance Criteria For New Drug Substances And New Drug Products. The most commonly employed dissolution test methods as described in the European Pharmacopeia 6.3 (6th edition) are the basket method (Apparatus 1) and the paddle method (Apparatus 2). The described methods are simple, robust, well standardized, and used worldwide. They are flexible enough to allow dissolution testing for a variety of drug products. The following parameters influencing the dissolution behaviour may for example be relevant for selecting the appropriate in vitro dissolution test conditions for an immediate release solid oral product: Apparatus, stirring speed, dissolution medium and temperature.
BIBW 2992 is known as the compound 4-[(3-chloro-4-fluorophenyl)amino]-6-{[4-(N,N-dimethylamino)-1-oxo-2-buten-1-yl]amino}-7-((S)-tetrahydrofuran-3-yloxy)-quinazoline,

BIBW 2992 is a potent and selective dual inhibitor of erbb1 receptor (EGFR) and erbB2 (Her2/neu) receptor tyrosine kinases. Furthermore, BMW 2992 was designed to covalently bind to EGFR and HER2 thereby irreversibly inactivating the receptor molecule it has bound to. This compound, salts thereof such as the dimaleate BIBW 2992 MA2 and its crystalline modification, their preparation as well as pharmaceutical formulations comprising BIBW 2992 or a salt thereof are disclosed in WO 02/50043 and WO 2005/037824. These documents are incorporated by reference regarding these aspects. BIBW 2992 BS mentioned hereinafter means the compound as the free base, identical with BIBW 2992 as characterized by the formula above.
BIBW 2992 is suitable for the treatment of tumoral diseases, hypersecretory diseases of the lungs and respiratory tract, diseases of the gastrointestinal tract, the bile duct and gall bladder. Indications to be treated with BIBW 2992 and combination treatments are disclosed in WO 2007/054550 and WO 2007/054551.